The present invention relates to corona charging devices, and more particularly to customer replacement components for corona chargers.
There are numerous prior art disclosures detailing the use of charging devices within various types of reprographic machines, or printing devices, to control the polarity on various elements within the reprographic machine. Charging devices are especially useful in reprographic machines that employ electrostatics to control charge levels, condition image receiving elements as well as various parts of reprographic machines, and insure that charges are of the intended polarity. Corona chargers used within conventional reprographic machines typically require specially trained field service personnel to change the chargers after failure, or when their intended period of use is completed. In general, a corona charger is a high maintenance device, especially in high end printing devices that generate a high number of prints, and require qualified technicians or field service personnel to change the chargers. These high-end printing devices have particular actions items that need to be performed in a highly accurate manner. Actions such as dismounting the charger from the machine, removing covers on the machine or charger assembly, removing the wire used to for the corona charger, cleaning the charger body, putting back the assembly or covers, and mounting the chargers into the machine must be done in a manner that is essentially foolproof. In order to insure that proper maintenance is carried out on these high-end machines, specially trained personnel are typically required. The requirement of specially trained personnel can result in significant periods of downtime for the machine, which is an unacceptable loss for the owner/operator of a high-end printing device. To eliminate the need for specially trained personnel, a charger assembly is required that can quickly be replaced without requiring adjustments to be made.
In view of the foregoing discussion, there remains a need within the art for a device that allows the changing of charging devices by the owner/operator in short periods of time without the necessity of specially trained personnel. Additionally, there is a need for charging devices for high end printing machines that use interchangeable parts.
The present invention addresses the aforementioned needs within the prior art by providing a corona-charging device assembly that can quickly be replaced by the user/operator of a reprographic machine without requiring any adjustments in the charger assembly, resulting in significant increases in the up time exhibited by the reprographic machine. The up time is the amount of time that the machine is running and, therefore, available to produce high quality prints. Reprographic machines intended to produce large amounts of high quality prints are intended to have high reliability characteristics. The invention addresses these needs by providing a charger in the form of an operator replaceable component (ORC) for corona and web-charging devices.
The number of actions that the user/operator is required to perform and the difficulty of these actions are minimized by the charging device assembly structure of the present invention. There are certain actions that routinely need to be performed without the necessity of adjustments, and these actions need to be accomplished in a relatively foolproof manner. Actions such as dismounting the charger from the machine, removing any covers on the body, removing the wire corona, cleaning the charger body, putting the covers back on to the charger body, and mounting the chargers into the machine are critical to increasing the amount of up time of a reprographic machine.
The invention teaches a charging apparatus that can be used on a system having multiple charger assemblies. In the preferred embodiment, there are numerous web-charging assemblies including charging devices that tack down the receiver elements to the web, control potential levels between modules, detack the receiver elements from the web, and condition the web to be at a predetermined potential level. The invention provides a charging device that can readily be adapted to accomplish in an assembly that can be serviced by the user without requiring special tools.
The charger assembly of the invention provides every feature that is considered critical within a charging device mechanical assembly, and includes a single operator replaceable component (ORC). The mechanical assembly for the charging device includes the critical parts having the necessary measurements and adjustments already made to provide for the correct spatial configurations. These critical distances include the spacing between corona wires, ensuring equal distance between the web and the corona wires; the size of the gap between the wire and the ground plane or the charger grid, and the length of the corona wire among others.
In the preferred embodiment, the charger assembly is employed in a high-end digital printing device that uses charging devices to control potential levels throughout the system. High-end printing devices inherently use multiple charging devices and for high-end color, printing devices will require more charging devices. The mechanical assembly of the invention is used as an ORC for every charging device in the system, resulting in a more reliable reprographic machine.
The invention provides for sliding the charging device assemblies out of their operating positions within the digital printing device for performing actions that entail removal of the assembly. It should be noted that in performing the actions necessary to remove the charger assembly from the digital printing device, there is no need to remove any bracket or to unlock the charger. Additionally, the removal of a high voltage connector is invisible to the customer (blind mate HV connection). To disassemble the components of a charger, the front and rear covers have snap features that wrap around the end of the charger body and do not require the use of any tools. The removal of the corona wire is simplified by first removing the tension of the wire and then removing the wire form the assembly. The disassembly of the grid is accomplished by sliding the grid out from the charger body.
The invention has the advantage in that the same parts can be used in several charger applications. The same charger body can be used in the intermodule chargers, detack chargers, conditioner chargers without a grid, and conditioner chargers with a grid. The same rear covers can be used in all chargers bodies (intermodule, detack, and conditioners). The corona wires are the same in all chargers. Just one corona wire length can be used in numerous applications. The front end is the same in all chargers. The interchangeability of parts avoids confusion in inventory and reduces the number of parts that must be inventoried.
Additional advantages result from the ability to precisely locate the web between conditioner chargers and their associated grids.
The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiment presented below.